Viljelusviiside mõju nisu tärkliseterade omadustele
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Kuupäev
2017
Kättesaadavus
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Nisu katab olulise osa inimese toidulauast. Tärklis moodustab suurema osa nisu terisest ja
tärklise kvaliteet mõjutab nisust saadava jahu kvaliteeti. Käesoleva uurimustöö
eesmärgiks oli uurida mahe- ja tavasüsteemis kasvatatud talinisu tärklise omadusi. Töö
eesmärkideks oli välja töötada protokoll tärkliseterade analüüsimiseks ning välja
selgitada, kas viljelusviis ja väetusvariandid omavad mõju talinisu tärklise graanulite
suurusele ja arvukusele ning kas tärkliseterade ja kvaliteedinäitajate vahel on olulisi
seoseid.
Töö hüpotees oli, et viljelusviis ja lämmastikunorm mõjutab tärkliseterade suurust ja
maheviljelusviisil kasvatatud nisul on tärkliseterade läbimõõt väiksem kui
tavaviljelusviisil kasvatatud nisul.
Töös analüüsiti nisuproove, mis koguti viljelusviiside võrdluskatselt aastatel 2015 ja
2016. Tärkliseterad eraldati kahel erineval meetodil ning täkrliseterade suurused ja
arvukused mõõdeti samuti kahel erineval meetodil, käsitsi mikroskoobiga ja laseriga.
Viljelusviis ei oma mõju tärkliseterade läbimõõdule ja arvukusele. Peamiseks mõjutajaks
uuritaval perioodil on kasvuaegne ilmastik. Samuti leidub seos tärkliseterade läbimõõdu ja
arvukuse vahel.
Kui tärkliseterade keskmine läbimõõt väheneb, siis tärkliseterade koguarv suureneb; kui
keskmine läbimõõt suureneb, siis koguarv väheneb. Mida väiksem on tärkliseterade
keskmine läbimõõt ja mida suurem koguarv, seda suurem on ka talinisu terasaak. Suurema
terasaagi puhul esimesel jahvatamisel saadav peenjahu kogus väiksem kui madalama
terasaagi puhul. Mida rohkem (ja väiksema läbimõõduga) on tärkliseterad, seda suurem
on nisu terise mahumass.
Kuigi käesoleva töö tulemused seatud hüpoteesi ei toeta, on testitud protokolli abil
võimalik analüüsida tärkliseterasid suuremas mahus, et anda kindlamat hinnangut
viljelusviisi mõju kohta.
Wheat is a staple food for humans. The majority of the wheat seed is starch. The quality of starch has impact on the quality of products made down the line. Therefore, the aim of the current study was to analyze the starch granules in different farming systems. More specifically, the aim was to develop a protocol to extract starch from the seed and to analyze its size distribution. The second aim was to characterize the starch granules in each farming system and to find correlations between starch, farming system and quality criteria. The hypothesis was set that starch granules are smaller in the organic farming system. Wheat samples were collected in 2015 and 2016 from the long-term field experiment. Starch was extracted manually directly from the seed. Also the byproduct of gluten index measurement protocol was used to starch extraction. The size distribution of starch granules was measured manually with the microscope and mechanically with the laserdiffraction particle size analyzer. The farming system had no statistically significant impact on the starch granule size distribution. The weather conditions had the biggest impact. However, there was a clear correlation between diameter and number of starch granules. If the size of wheat starch granule decreases, the amount of granules increases. If the size increases, the amount decreases. Smaller granules means higher wheat yield. Higher yield gives less fine flour during first milling. Bigger amount of granules makes wheat grain harder and gives it bigger volume mass. Those grains are hard to grind and they give less fine flour during the first milling. Even though the current study did not provide proof for the set hypothesis, it yielded a good study protocol to conduct the analysis on larger scale to properly assess the impact of the farming system on the starch granules.
Wheat is a staple food for humans. The majority of the wheat seed is starch. The quality of starch has impact on the quality of products made down the line. Therefore, the aim of the current study was to analyze the starch granules in different farming systems. More specifically, the aim was to develop a protocol to extract starch from the seed and to analyze its size distribution. The second aim was to characterize the starch granules in each farming system and to find correlations between starch, farming system and quality criteria. The hypothesis was set that starch granules are smaller in the organic farming system. Wheat samples were collected in 2015 and 2016 from the long-term field experiment. Starch was extracted manually directly from the seed. Also the byproduct of gluten index measurement protocol was used to starch extraction. The size distribution of starch granules was measured manually with the microscope and mechanically with the laserdiffraction particle size analyzer. The farming system had no statistically significant impact on the starch granule size distribution. The weather conditions had the biggest impact. However, there was a clear correlation between diameter and number of starch granules. If the size of wheat starch granule decreases, the amount of granules increases. If the size increases, the amount decreases. Smaller granules means higher wheat yield. Higher yield gives less fine flour during first milling. Bigger amount of granules makes wheat grain harder and gives it bigger volume mass. Those grains are hard to grind and they give less fine flour during the first milling. Even though the current study did not provide proof for the set hypothesis, it yielded a good study protocol to conduct the analysis on larger scale to properly assess the impact of the farming system on the starch granules.
Kirjeldus
Magistritöö
Põllumajandussaaduste tootmise ja turustamise õppekaval
Märksõnad
magistritööd, talinisu, kvaliteet, tärklis, maheviljelus, tavaviljelus